UNIVERSITY   OF    CALIFORNIA 

COLLEGE    OF    AGRICULTURE 

AGRICULTURAL   EXPERIMENT  STATION 

CIRCULAR  No.  278 
September,  1924 

Olive  Pickling  in  Mediterranean  Countries 

BY 

W.  V.  CEUESS 


Although  olives  are  grown  in  the  Mediterranean  countries  prin- 
cipally for  oil,  a  considerable  portion  of  the  crop  is  used  for  the 
preparation  of  various  kinds  of  pickled  and  cured  olives.  Some  of 
the  olives  are  prepared  by  processes  similar  to  that  in  use  for  ripe 
olives  in  California;  others  by  processes  that  are  distinctly  different. 
The  various  processes  may  be  classified  as  follows : 

1.  The  Spanish  green  olive  process. 

2.  The  French  process. 

3.  The  brine  process. 

4.  The  dry  salt  process. 

5.  The  water  process. 

6.  The  Italian  dried  olive  process. 

In  the  Spanish  and  French  processes  lye  is  used  to  destroy  all  or 
most  of  the  bitterness ;  in  the  other  processes  lye  is  not  used. 

Brine  or  salt  cured  olives  are  preferred  by  southern  European 
consumers,  while  the  Spanish  lye-treated,  fermented  olives  are  most  in 
demand  for  export.  However,  important  quantities  of  brine  or  salt 
cured  olives  are  imported  by  the  United  States  and  consumed  by 
people  of  southern  European  origin. 

While  the  Californian  olive  industry  depends  at  present  upon  the 
black  olive,  it  is  probable  that  profitable  markets  could  be  developed 
for  limited  quantities  of  other  types.  It  is  for  this  reason  that  the 
European  methods  are  described  in  this  publication.  The  material 
presented  was  obtained  during  a  recent  visit  to  the  olive  districts  of 
southern  Europe.  Thanks  are  due  to  the  California  Ripe  Olive 
Association  for  financial  assistance  which  made  the  trip  possible. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


CULTURE  OF  OLIVES  USED  FOR  PICKLING 

European  cultural  practices  in  the  growing  of  olives  for  pickling 
differ  in  several  important  respects  from  those  in  use  in  California. 
A  brief  resume  of  observations  upon  olive  culture  in  olive  pickling 
districts  of  Spain  and  France  should  be  of  interest  to  California 
growers.  Little  first  hand  information  on  the  growing  of  olives  for 
pickling  in  Italy  was  obtained,  most  of  the  observations  in  Italy  being 
made  upon  groves  in  which  the  olives  are  grown  for  oil  making. 

Spain.- — The  industry  is  confined  to  a  small  area  surrounding 
Seville  in  southern  Spain.  Very  few  green  olives  are  prepared  at  a 
distance  exceeding  twenty  miles  from  this  city.  The  reason  given  for 
this  situation  is  that  only  the  olives  of  the  Seville  district  possess  the 
proper  quality  for  green  pickling. 

The  olives  are  grown  for  the  most  part  on  large  estates  known  as 
"fincas, "  in  this  respect  differing  from  conditions  in  northern  Spain 
and  southern  France,  where  small  orchards  prevail. 

Extent  of  the  Green  Olive  Industry. — W.  T.  Gracey,  former 
American  consul  at  Seville,  placed  the  total  area  of  olive  plantings 
in  Spain  in  1915  at  about  3,600,000  acres.  According  to  the  same 
authority,  the  crop  of  Spain  in  a  recent  year  was  approximately 
1,953,700  tons  of  olives  for  all  purposes,  and  of  these  the  province  of 
Seville  produced  379,300  tons.  Only  21,000  tons,  or  about  1.7%  of  all 
the  olives  of  Spain  or  5.6%  of  those  of  Seville  were  used  for  green 
pickles.  The  production  in  1922  was,  according  to  the  American 
Consul  W.  C.  Burdette  of  Seville,  3,280,000  gallons  of  green  pickles 
(20,500  fanegas  =  9,900  tons)  ;  in  1921,  5,600,00  gallons  and  in  1920, 
9,600,000  gallons  (29,000  tons).  Evidently  production  varies  greatly 
from  year  to  year,  and  apparently  Spanish  olive  growers  are  unable 
to  overcome  the  tendency  for  olives  to  bear  irregularly. 

It  is  customary  to  assume  25  per  cent  of  the  total  production  to 
be  unsuitable  for  export.  According  to  Burdette,  in  1922  the  exports 
totaled  4,604,113  gallons  (includes  hold-over  from  1921)  and  brought 
$4,308,807,  f .o.b.  Seville ;  a  price  of  approximately  $0,936  per  gallon. 
This  represents  an  unusually  high  price — probably  at  least  twice  the 
average  price  of  previous  years. 

Propagation  of  Trees. — According  to  Mr.  Gracey,  former  American 
consul,  in  the  Seville  district  the  average  number  of  trees  to  an  acre 
varies  from  36  to  40. 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES  3 

Several  systems  of  propagating  trees  are  in  common  use.  Of 
these  the  most  important  are  the  following : 

a.  Estacas. — A  piece  of  an  olive  branch  17  to  20  inches  long  and 
about  2%  to  2%  inches  thick  is  planted  vertically  in  the  nursery  in 
a  hole  about  18  inches  deep.  Three  shoots  only  are  allowed  to  grow 
for  four  years  in  the  nursery.  The  estaca  is  then  transplanted  in  the 
late  summer  or  early  fall. 

The  young  trees  are  planted  in  a  hole  about  three  feet  deep  in  the 
bottom  of  which  is  placed  a  layer  of  manure  covered  with  earth.  Clay 
is  mounded  up  around  the  tree  to  a  height  of  two  feet  or  more  above 
the  ground  level  giving  the  appearance  of  an  ant  hill.  This  mound 
retains  the  moisture  and  prevents  formation  of  shoots  near  the  base 
of  the  ' '  estaca. ' '  A  hole  is  left  half  way  up  the  mound  and  through 
this  the  tree  is  watered  at  the  time  of  planting  and  several  times  during 
the  fall,  if  rains  are  late. 

b.  Garrotes. — These  are  pieces  of  pruning  wood  of  about  the  size 
mentioned  above  for  estacas,  planted  in  the  nursery  two  in  a  place, 
with  the  two  pieces  leaning  toward  each  other  forming  a  triangle  with 
the  apex  even  with  the  ground.  Only  one  shoot  from  each  "garrote" 
is  allowed  to  grow,  giving  two  trees  from  each  hole  for  transplanting. 
Trees  from  estacas  bear  in  four  to  five  years;  those  from  garrotes  in 
eight  to  ten. 

c.  Zuecas. — These  are  protuberances  ("ovoli"  of  the  Italians) 
cut  from  the  tree  and  planted  either  direct  in  the  orchard  or  in  the 
nursery  to  be  transplanted  later. 

d.  Raices. — These  represent  root  cuttings  used  for  propagation. 

e.  Retofws. — These  are  suckers  cut  from  the  tree  beneath  the 
ground. 

/.  Grafting. — Wild  trees  or  undesirable  varieties  of  cultivated  trees 
are  often  grafted  in  place  in  the  orchard.  Seeds  of  wild  olives  are 
also  planted  in  the  nursery  and  the  young  seedlings  from  the  nursery 
planted  in  the  orchard  to  be  grafted  later.  According  to  one  of  the 
large  packers,  who  is  familiar  with  cultural  methods,  the  better  olive 
growers  prefer  trees  of  Sevillano  and  other  pickling  varieties  grafted 
on  wild  olive  roots  to  trees  grown  from  estacas  or  other  forms  of 
cuttings. 

March  is  considered  the  best  month  for  grafting  in  the  Seville 
district.  Cleft  grafts  with  four  to  five  buds  or  bark  grafts  are  used. 
Owing  to  the  large  demand  for  Sevillano  and  Manzanillo  olives  during 
the  past  two  or  three  years,  a  considerable  number  of  oil  olive  trees 
are  being  grafted  with  pickling  varieties. 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

Irrigation. — In  most  seasons  the  rainfall  is  sufficient  to  produce 
fruit  of  good  pickling  quality  and  irrigation  of  the  orchards  is  not 
usually  practiced.  Inadequate  rainfall  and  very  hot  summers  occa- 
sionally cause  the  fruit  to  be  smaller  than  is  desired  for  pickling. 
This  was  the  case  in  1923. 

Cultivation. — Soil  moisture  is  conserved  by  three  or  more  plowings 
or  cultivations  to  prevent  excessive  growth  of  weeds  and  grass.  In  a 
few  orchards  wheat  or  some  other  field  crop  is  grown  between  the 
rows,  but  this  practice  results  in  small  fruit  and  poorly  nourished  trees. 
The  usual  plow  is  home  made.  It  has  one  handle,  a  wooden  beam  and 
steel  share.    See  fig.  1. 


Hi 


Fig.  1. — Typical  plow  and  ox  team.     Near  Seville. 

Pruning. — Pruning  has  a  very  important  place  in  olive  culture  in 
the  Seville  district.  Two  systems  are  used,  an  annual  and  a  biennial. 
In  the  annual  system  the  trees  are  pruned  lightly  every  year ;  in  the 
biennial,  somewhat  more  severely  once  every  two  years.  In  each 
system  the  object  is  to  promote  regular  bearing  by  causing  the  tree 
to  exhibit  a  suitable  supply  of  two-year  wood  every  season.  In  both 
systems  the  center  of  the  tree  is  made  open  and  the  crowding  of 
branches  and  twigs  prevented  by  thinning  out  surplus  wood.  The 
trees  and  particularly  the  centers  are  much  more  open  than  in  Cali- 
fornia. The  objects  of  pruning  as  practiced  in  the  orchards:  of  Seville 
are  given  by  Guillen-Gareia*  as  follows : 

*  101  Olivo,  by  D.  Guillermo  J.  de  Guillen-Garcia,  1917.  Libreria  de  Francisco 
Ping,  Plaza  Nueva  5,  y  Capellanes  2,  Barcelona,  Spain.     Publishers. 


Circular  278]     olive  pickling  in   mediterranean   COUNTRIES  5 

"1.  To  obtain  new  growth  for  the  crop  of  two  years  hence. 

2.  To  admit  sunlight  to  aid  in  the  setting  of  the  fruit. 

3.  To  eliminate  upright  branches,  which  do  not  bear  fruit. 

4.  To  remove  dead  and  non-bearing  wood. 

5.  To  adjust  the  size  of  the  tree  to  the  water  supply  and  the  fer- 

tility of  the  soil. 

6.  To  avoid  excess  of  fruiting  wood,  which  excess  would  give  small 

fruit. 

7.  To  avoid  biennial  bearing;  leaving  too  little  old  wood  stimu- 

lates excessive  new  growth  and  biennial  bearing. 

8.  To  avoid  high  trees,  which  are  costly  to  harvest  and  which  bear 

little  fruit. 

9.  To  be  so  conducted  as  to  avoid  cutting  off  main  branches  or 

trunk. ' ' 


Fig.  2. — Sevillano  olive  tree  before  and  after  pruning.     Near  Seville. 

Fig.  2  illustrates  the  two-year  pruning  method. 

Ringing. — Ringing  is  sometimes  employed  to  obtain  larger  fruit, 
earlier  ripening  and  better  setting.  A  strip  one-fourth  to  one  inch 
wide  is  removed  from  the  bark  of  the  large  branches  when  the  tree 
has  begun  to  blossom  but  before  the  flowers  have  completely  developed. 
Girdling  or  ringing  in  this  manner  retards  flow  of  sap  downward  and 
forces  it  into  the  fruit  with  results  noted  above. 

Fertilization. — Manure  and  commercial  fertilizers  are  used  in  many 
orchards.  The  manure  and  fertilizer  are  buried  in  a  circular  ditch 
dug  around  each  tree.  Annual  applications  are  considered  better  than 
biennial  or  triennial,  because  they  induce  more  regular  bearing. 
According  to  W.  T.  Gracey,*  former  American  consul  at  Seville,  30  to 


*  Gracey,  W.  T.     Olive  Growing  in  Spain.     Special  Consular  Keport  No.  79, 
From  Superintendent  of  Documents,  Washington,  D.  C.     5  cents. 


6  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

40  pounds  of  barnyard  manure  and  3%  pounds  of  superphosphate  are 
applied  to  each  tree.  Sodium  nitrate  or  ammonium  sulfate  1%  to 
2  pounds,  iy2  to  2  pounds  of  potassium  chloride,  and  3  to  4  pounds  of 
gypsum  are  also  desirable.  Proper  fertilization  promotes  the  setting 
of  the  fruit  and  increases  the  size ;  but  if  too  abundant,  overstimulates 
leaf  production  and  decreases  fruiting. 

Spanish  growers  to  whom  the  writer  talked  believed  that  irregular 
production  in  California  may  be  due  principally  to  improper  pruning 
and  lack  of  fertilizers.  Superphosphate  is  considered  the  most  import- 
ant ingredient  of  chemical  fertilizers  in  causing  fruit  to  set  properly. 

Insect  Pests. — The  most  important  insect  pest  is  the  olive  fly,  Dacus 
oleae  (in  Spanish  "la  mosca  del  olivo, "  in  French  "la  mouche  de 
1 'olive")-  The  fly  is  much  more  destructive  in  olive  districts  of 
northeastern  Spain  than  in  Seville,  although  even  here  it  does  great 
damage  in  some  seasons. 

The  fly  is  a  small  dipterous  insect  about  5  millimeters  in  length 
(about  one-fifth  of  an  inch).  According  to  a  prominent  olive  packer 
of  Seville,  the  first  generation  of  the  fly  in  the  Seville  district  emerges 
from  the  soil  in  June  or  July.  The  female  deposits  its  eggs  in  the 
flesh  of  the  olive  through  the  skin,  usually  one  egg  to  each  olive.  One 
female  may  deposit  100  or  more  eggs.  On  the  green  olive  a  small 
black  spot  marks  the  spot  where  the  ovipositor  of  the  fly  has  been 
inserted.  According  to  Minangoin,*  the  egg  hatches  in  from  2  to  6 
days,  according  to  the  temperature.  The  larva  develops  rapidly  and 
reaches  the  pupal  stage  after  12  to  15  days.  During  this  period  it  is 
very  active  in  forming  galleries,  particularly  around  the  pit,  and  in 
eating  its  way  through  much  of  the  pulp.  The  olive  becomes  soft  and 
rancid  and  wholly  unfit  for  pickling.  It  is  usually  unfit  also  for  good 
oil,  yielding  a  rancid  oil  of  poor  flavor. 

The  larva  may  pupate  immediately  beneath  the  skin  of  the  olive 
or  may  emerge  from  the  olive  and  pupate  at  some  other  point,  such 
as  under  the  bark  or  in  the  soil.  In  10  or  12  days  in  warm  Weather, 
or  from  20  to  24  days  in  autumn,  the  adult  insect  appears  and  the 
cycle  begins  again  by  insertion  of  eggs  in  the  olives.  This  second 
generation  may  appear  in  late  summer  or  early  autumn.  In  favorable 
years  a  third  generation  develops.  It  is  the  second  and  third  genera- 
tions that  are  most  destructive. 

In  very  dry  years  the  olives  are  small  and  very  hard  at  the  time  of 
the  appearance  of  the  first  generation  in  early  summer  and  very  few 
of  the  insects  find  suitable  fruit  for  the  deposition  of  their  eggs.    Con- 

*  Minangoin,  N.  Maladies  et  Insectes  de  1 'Olivier.  Compte-Kendu  General 
de  Congres  Oleicole  de  Sousse,  1910,  pp.  99,  119. 


CIRCULAR  278]       OLIVE  PICKLING    IN    MEDITERRANEAN    COUNTRIES  7 

sequently,  the  second  generation  is  few  in  numbers  and  the  damage 
slight.  This  was  the  case  during  the  1923  season  in  the  Seville  district, 
where  it  was  very  difficult  to  find  infested  olives  last  October.  In 
Tortosa,  however,  where  weather  conditions  had  been  favorable  to  the 
insect,  90  to  100  per  cent  of  the  olives  were  infested  and  it  was  difficult 
to  find  specimens  of  sound  fruit.    Many  olives  contained  two  larvae. 

The  danger  increases  as  the  fruit  nears  maturity ;  hence  every  effort 
is  made  to  harvest  as  soon  as  the  olives  are  large  enough  for  pickling. 
To  allow  the  olives  to  reach  the  stage  of  maturity  before  pickling,  at 
which  olives  are  picked  in  California,  would  be  very  hazardous,  accord- 
ing to  growers  and  packers  of  Seville  who  were  interviewed  on  this 
point.  Although  olives  with  a  small  amount  of  color  can  be  used  for 
green  pickling,  danger  of  injury  by  the  fly  is  greatly  increased  by 
allowing  the  olives  to  reach  this  degree  of  ripeness.  There  is,  there- 
fore, little  probability  that  Seville  olive  packers  will  attempt  to 
duplicate  the  California  ripe  olive  pickle. 

Infestation  is  usually  much  less  severe  in  the  province  of  Seville 
than  in  the  northern  districts  of  Spain,  and  little  effort  is  made  to 
combat  the  pest.  In  Tortosa  the  Lotrionte  method  is  employed.  This 
consists  in  suspending  in  the  tree  a  small  box  filled  with  leaves  kept 
wet  by  frequent  applications  of  syrup  poisoned  with  arsenate  of  soda. 
The  method  is  not  very  efficacious.  The  Berlese  system  consists  in 
spraying  the  trees  frequently  with  a  sweetened  arsenical  solution. 
This  has  proved  fairly  satisfactory  in  Tuscany  in  Italy,  where  it  has 
been  applied  in  orchards  over  a  very  large  area.  The  insect  normally 
feeds  on  the  honey  dew  secreted  by  insects  or  upon  other  sweet 
liquids — hence  the  use  of  poisoned  syrups.  The  use  of  contact  sprays 
is  not  effective.  Control  by  insects  parasitic  upon  the  fly  is  under 
investigation  but  is  still  in  the  experimental  stage.  ' '  Opius  concolor, ' ' 
an  insect  from  northern  Africa,  gives  most  promise  as  a  parasite.  Dr. 
Silvestri  of  the  College  of  Agriculture  of  Portici,  Italy,  has  done  a 
great  deal  of  research  upon  the  use  of  this  and  other  olive  fly  parasites. 

In  general,  an  effective  method  of  control  of  the  olive  fly  has  not 
yet  been  found  and  its  ravages  are  widespread  and  increasing.  Unless 
an  effective  and  economical  method  can  be  found,  many  olive  plantings 
in  northeastern  Spain  must  be  abandoned. 

Considerable  damage,  also,  is  done  by  the  larvae  of  an  insect  that 
penetrates  the  seed  of  the  small  fruit,  causing  it  to  fall  from  the  tree 
prematurely.  Scale  insects  are  common,  and  the  honey  dew  secreted 
by  them  provides  food  for  the  sooty  mold  fungus  ("la  negra"),  which 
often  covers  the  leaves  and  may  injure  the  appearance  of  the  fruit  for 
pickling. 


<3  «  UNIVERSITY    OF  '  CALIFORNIA EXPERIMENT    STATION 

Diseases. —Olive  knot  is  very  prevalent  and  undoubtedly  reduces 
the  crop.'- -One  grower  stated  that  it  is  frequently  necessary  to  replace 
badly  affected  trees."  Many  large  trees,  about  10  inches  or  more  in 
diameter,  are  affected  by  heart  rot— many  are  hollow;    See  fig.  3. 

According  to  growers  and  agricultural  experts  interviewed,  little 
effort  is  made  to  control  these  various  pests  and  diseases,  although  ii 


Fig.  3. — Old  olive  tree  showing  heart  rot.     Near  Seville. 

is  believed  that  pruning  exerts  an  inhibitive  effect  by  admitting  direct 
sunlight  to  all  parts  of  the  tree. 

Olive  Varieties. — There  are  more  than  twenty  varieties  of  olives 
grown  commercially  in  southern  Spain  but  only  two  are  used  exten- 
sively for  green  pickling.  These  are  the  Sevillano  ("Queen"  or 
"Gordal")  and  the  Manzanillo — apparently  the  same  as  the  varieties 
grown  in  California  under  these  names. 


.Circular  278]     olive  pickling  in  mediterranean  countries  9 

The  Zorzalena,  a  small  olive  similar  in  shape  to  the  Mission  olive, 
is  the  principal  variety  grown  in  southern  Spain  for  oil  and  is  some- 
times used  for  pickling  for  local  consumption.  The  Rapasayo  resembles 
the  Manzanillo  somewhat  in  form  but  is  larger  and  of  firmer  flesh.  It 
is  not  considered  quite  equal  to  the  Manzanillo  for  green  pickles  but 
is  occasionally  used  for  green  pickling,  when  the  Manzanillo  crop  is 
small.  The  Cordovi  is  a  very  large  olive,  nearly  spherical  in  shape, 
but  said  to  be  too  tender  for  green  pickling.  The  Murcal  is  a  very 
large  variety,  but  not  so  suitable  as  the  Sevillano  for  green  pickling, 
because  of  its  large  pit  and  poor  texture.  In  several  factories  an  olive 
very  similar  in  appearance  to  the  Mission  of  California  was  seen.  By 
one  pickler  it  was  called  the  "Moron, ' '  but  a  prominent  exporter  stated 
that  this  name  is  generally  used  to  designate  a  grade  of  Manzanillo 
olives.  The  "Moron"  olive  is  used  for  pickling  for  local  consumption. 
The  Madrileno  is  a  very  large  olive  with  a  small  pit,  according  to  Mr. 
Gracey,  but  the  writer  was  unable  to  locate  this  variety  in  Seville.  It  is 
said  to  be  satisfactory  for  pickling  and  equal  to  the  Sevillano  in  size. 

It  is  probable  that  one  or  more  of  the  larger  varieties  such  as  the 
Murcal,  Cordovi,  Rapasayo,  and  Madrileno,  would  be  suitable  for  ripe 
pickling. 

France. — Olives  are  grown  in  France  throughout  the  region  border- 
ing the  Mediterranean  Sea,  The  most  important  pickling  establish- 
ments are  situated  in  the  district  surrounding  Nimes.  Most  of  the 
fruit  in  other  districts  is  used  for  oil-making. 

Varieties. — Several  varieties  are  used  for  pickling.  The  most 
important  according  to  J.  Bonnet,  Director  of  the  Olive  Department  of 
the  French  Ministry  of  Agriculture,  are  the  Picholine,  the  Verdale, 
the  Lucques,  and  the  Amellau.  Others  used  in  commercial  quantities, 
according  to  A.  Rolet  of  the  College  of  Agriculture  at  Antibes,  are  the 
Salonenque,  Oliviere,  Espagnole  (Sevillano),  Bouteillan,  and  Gros- 
sanne.  The  Amellau  is  a  very  large  olive.  Samples  seen  in  the  office 
of  J.  Bonnet  equalled  the  Sevillano  in  size.  The  Picholine  Is  a  large 
olive  curved  near  the  blossom  end.  It  is  not  the  Redding  Picholine 
which  is  a  very  small  seedling  olive  distributed  by  mistake  in,  California 
as  the  Picholine.  The  Verdale  resembles  the  Manzanillo  somewhat  in 
shape  but  is  probably  larger.  The  Lucques  is  elongated  and  much 
curved,  i.e.,  somewhat  crescent-shaped.  It  is  of  excellent  flavor.  It 
is  probable  that  the  Amellau  and  Picholine  would  be  of  value  for  ripe 
pickling  in  California.  Most  of  the  ripe  pickles  seen  in  Nimes  were 
of  the  Picholine  variety. 

Culture. — The  culture  of  olives  for  pickles  in  France  differs  from 
that  in  Seville,  particularly  in  regard  to  pruning.     The  trees  in  the 


10 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


neighborhood  of  Nimes  and  Aix-en-Provence  are  pruned  much  more 
severely  than  in  Seville.  The  center  of  the  tree  is  kept  open ;  horizont 
rather  than  vertical  branches  are  retained;  the  tree  is  "headed  back" 
after  the  fashion  of  apricot  trees  by  a  moderate  "short  pruning" 
system ;  and  in  addition  considerable  thinning  is  done.  The  pruning 
is  annual  more  often  than  biennial.  It  is  believed  that  occasional 
severe  pruning  is  necessary  to  induce  the  formation  of  new  wood  and 
the  object  is  to  obtain  a  good  supply  of  two-year-old  wood,  which  bears 


Fig.  4. — Olive  tree  after  pruning.     Nimes,  France.     Illustrating  severe 
pruning  given  once  in  three  or  four  years. 


the  fruit.  See  fig.  4.  It  must  be  remembered  that  the  climate  at  Nimes 
is  cooler  than  at  Seville  and  the  soil  poorer.  Therefore,  it  is  possible 
that  these  conditions  account  for  the  difference  in  pruning  methods 
in  the  two  districts. 

In  the  Nice  district  on  the  shores  of  the  Mediterranean  the  trees 
grow  luxuriantly  and  become  very  large.  Here  pruning  consists  in 
"dehorning"  (severely  cutting  back)  the  trees  once  in  three  or  four 
years. 


Circular  278]     olive  pickling  in  mediterranean  countries 


11 


Irrigation  is  seldom  used  in  France.  Fertilization,  however,  both 
with  barnyard  manure  and  commercial  fertilizers  is  a  common  prac- 
tice. J.  Bonnet  stated  that  proper  fertilization  in  France  is  essen- 
tial to  regular  bearing  and  that  Californian  growers  would  profit  by 
making  use  of  the  experience  of  the  French  growers.  He  reports  the 
following  results  of  experiments  to  show  the  effect  of  fertilization  on 
yields  of  olives  in  French  olive  groves. 


TABLE  1 

Effect  of  Fertilization  on  Olive  Yields.     (After  J.  Bonnet) 

(Yields  per  Tree  in  Pounds) 

District 

Check 
untreated 

1%  lbs.  ammonium    Combination  of 
Green  cover  crop                                        sulfate,    2.2  lbs.        preceding  two 
plowed  under.     Barnyard  manure     superphosphate,              columns 
No  other               110  lbs.  per            %  lb.  potassium         (Manure  and 
addition                       tree                   sulfate  per  tree           fertilizers) 

Villeneuve 

14.08 

37.07                  38.72                        40.04                      42.90 

La  Fare 

2.42 

3.21                   8.80                         8.30                     13.68 

Ledenon 

33.44 

45.10                  50.50                        54.12                      67.45 

Le  Luc 

48.31 

86.90                 80.87                       70.40                     83.60 

Fig.  5. — Typical  olive  tree  near  Florence,  Italy, 
training  of  branches. 


Showing  horizontal 


Mr.  Bonnet  points  out  that  the  amounts  of  fertilizing  materials  to 
be  applied  will  vary  greatly  according  to  the  age  and  condition  of  the 
tree,  the  fertility  of  the  soil,  and  water  supply.  The  proper  amounts 
of  each  material  must  be  determined  for  each  region  by  trial.  In 
experiments  with  the  use  of  chemical  fertilizers  applied  singly 
ammonium  sulfate  gave  considerably  greater  increase  in  yield  than  did 
potassium  sulfate  or  calcium  superphosphate. 


12 


UNIVERSITY    OF    CALIFORNIA-^EXPERIMENT    STATION 


Italy. — Observations  made  in  Italy  were  upon  the  culture  of  oil 
olives  rather  than  of  pickling  varieties. 

The  principal  varieties  used  for  pickling  are  the  Santa  Catarina,  a 
large  olive  grown  in  southern  Italy  and  in  Sicily ;  the  Castriciano,  an 
olive  larger  than  the  Manzanillo  but  smaller  than  the  Ascolano  and 
somewhat  like  the  Mission  in  shape;  the  Oliva  Bianca  d'Ascoli,  prob- 


Fig.  6. — Olive  grove  on  hillside  near  Viaregio,  Italy.     Trees  planted 
closely  together. 

ably  the  same  as  the  Ascolano  of  California,  although  samples,  said 
to  be  of  this  variety,  seen  in  Rome  and  Florence  appeared  to  be  more 
enlarged  at  the  blossom  end  than  the  Ascolano  of  California;  .the 
Agostino,  an  olive  of  medium  size ;  the  Santagatese  and  the  Minuta. 

In  southern  Italy  and  Sicily  the  trees  grow  luxuriantly  when 
properly  cared  for.  Opportunity  was  not  afforded  to  study  cultural 
methods  at  first  hand.  In  Sicily  lemons  have  largely  replaced  olives 
and  olive  trees  are  for  the  most  part  neglected. 


Circular  278]      OLIVE  PICKLING   IN   MEDITERRANEAN   COUNTRIES 


12 


In  central  and  northern  Italy  it  is  customary  to  grow  other  crops 
such  as  hay,  garden  truck,  etc.,  between  the  rows,  which  are  planted 
far  apart.  In  the  Florence  district  the  trees  are  small  and  similar  in 
appearance  to  those  of  Nimes  in  France.  They  are  severely  pruned 
every  three  or  four  years  and  lightly  pruned  every  year.     Only'  the 


Fig.  7.— Olive  tree  near  Rome,  Italy.  '  Illustrating  severe  pruning  given 
.    once  in  three  or  four  years  in  central  Italy. 

horizontal  and  drooping  branches  are  retained.  Many  of  the  trees 
are  .actually .  umbrella  shaped.  This  method,  of  pruning  facilitates 
picking  and  is  believed  to  favor .  regular  bearing.  (See  figs.  5-8, 
inclusive^ ).,  Fertilization  is  regularly  practiced  but  the  trees  are  not 
irrigated.  Calcium  superphosphate  and  ammonium  sulfate  are  the 
most  commonly  used  commercial  fertilizers. 


14 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT   STATION 


PICKLING  PROCESSES 

The  processes  of  pickling  olives  in  the  various  Mediterranean 
countries  vary  considerably  according  to  the  country,  the  nature  of 
the  raw  material  and  the  character  of  the  market.  For  example  the 
Spanish  green  olive  pickling  process  is  used  for  pickling  olives  for  the 
Spanish  export  trade ;  while  the  Greek  and  brine  curing  processes  are 
applied  largely  to  olives  to  be  consumed  in  the  countries  where  the 
olives  are  grown. 


J 


Pig.  8. — Olive  pruning  instruments.     Castel  Euggiero,  Italy. 


A.  SPANISH  PROCESS 

About  two  months  was  spent  in  the  olive  districts  of  Spain  in  the 
study  of  olive  pickling,  and  related  subjects.  The  following  description 
of  the  Spanish  process  is  based  upon  observations  made  in  the  Spanish 
orchards  and  factories. 

Harvesting. — The  picking  season  usually  begins  after  September 
15  and  before  October  1  and  lasts  until  about  November  1.  The  fruit 
is  picked  for  green  pickling  after  it  has  reached  full  size,  but  before 
it  has  ripened  sufficiently  to  become  tender.  Fruit  with  a  faint  blush 
of  color  can  be  used,  as  this  color  disappears  during  pickling,  but  that 
which  is  entirely  green  or  straw  yellow  in  color  is  preferred.  Ripe 
fruit  is  apt  to  soften  or  turn  gray  during  pickling. 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES 


15 


Picking. — The  fruit  is  picked  into  small  woven  grass  or  wicker 
baskets  suspended  from  the  neck  of  the  picker.  It  is  done  from  the 
ground  or  from  straight  ladders.  See  fig.  9.  Great  care  is  taken  to 
avoid  bruising,  and  the  fruit  is  selected  for  size  and  maturity  as  it  is 
picked.  Several  pickings  are  necessary,  as  in  California,  in  order  to 
obtain  fruit  of  fairly  uniform  quality. 


Fig.  9. — Harvesting  Sevillano  olives  near  Seville. 

Sorting. — The  olives  are  transferred  to  larger  baskets  holding  about 
60  pounds.  See  fig.  10.  These  are  carried  by  cart  or  on  donkey-back 
to  the  field  sorting  tables  in  the  orchard  or  to  similar  tables  at  the 
orchard  headquarters  (hacienda).  Here  the  olives  are  placed  on  low 
tables,  before  which  sit  women  who  sort  out  ripe  fruit,  that  injured  by 
the  fruit  fly,  very  small  fruit  and  that  which  is  bruised.  See  fig.  11. 
The  ripe  and  small  fruit  is  sold  to  peddlers  who  pickle  it  and  sell  it 
locally — the  processes  of  pickling  used  for  this  fruit  will  be  described 
later.  The  damaged  fruit  is  used  for  oil-making  in  the  grower's  oil 
factory. 


16 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Most  packers  insist  that  the  grower  carefully  sort  his  fruit  before 
delivery.  This  makes  it  unnecessary,  in  most  cases,  for  the  packer  to 
sort  at  the  factory  before  pickling. 

The  Factories. — The  factories  are  located  either  in  Seville  or  in  the 
small  villages,  such  as  Alcala,  Dos  Hermanos,  San  Juan,  and  Comas, 
near  the  city.  The  pickling  factory  usually  consists  of  a  large  walled-in 
yard  capable  of  holding  1000  to  3000  hogsheads  of  olives.  At  one  side 
of  the  yard  is  a  large,  one-room  stone  building,  in  which  are  located 
the  lye  vats.    Above  this  room  or  on  an  elevated  platform  in  the  yard 


Fig.  10. — At  left:  receiving  basket  used  at  factory.     At  right:  field  basket 

used  in  groves.  I 

are  the  lye  mixing  and  brine  tanks.  Some  -factories*  have  these  tanks 
below  the  floor  and  elevate  the  liquids  by  pump  "to  the  vats  or  hogs- 
heads. Usually  at  some  distance  from  the  lye-treating  room  are  one 
or  more  larger  buildings,  in  which  grading,  pitting,  stuffing  (see  p.  25), 
and  packing  of  the  pickled  olives  are  conducted. 

Transporting  and  Receiving. — The  olives  are  transported  from  the 
small  or  very  hilly  groves  by  burros.  Large  side-bags  or  ' '  angorillas ' ' 
hold  the  fruit — each  animal  carrying  about  200  pounds.  Trains  of 
12  to  15  burros  are  common.    See  fig.  12. 

From  the  larger  groves  the  fruit  is  usually  conveyed  in  large  high- 
wheeled  carts,  the  beds  of  which  are  lined  with  soft  grass  matting  to 
minimize  bruising.     Flexible  cloth  or  woven  grass  spouts  beneath  the 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES 


17 


cart  or  "angorilla"  permit  the  olives  to  be  unloaded  without  much 
handling"  and  bruising.  Some  of  the  fruit  is  carried  on  flat  cars  or  in 
carts  in  large  woven  grass  baskets.  A  few  motor  trucks  are  in  use,  but 
oxen  and  mules  are  more  usual.    See  figs.  13  and  14. 

Shallow,  rather  flexible,  "two-man"  baskets  receive  the  fruit  and 
are  used  in  place  of  the  lug  boxes  found  in  California  factories.  See 
fig.  10. 

The  packers  usually  insist  that  the  fruit  be  delivered  before  it  has 
begun  to  heat  in  the  field  baskets  after  picking.  Heating"  is  evidence 
of  bacterial  growth.    This  is  a  common  source  of  infection  and  causes 


Fig.  11. — Sorting  olives  at  the  orchard  before  delivery  to  factory.    Near  Seville. 


sliminess  and  deterioration  during  pickling,  storage,  and  shipment.  If 
affected  fruit  does  not  actually  spoil,  at  least  its  quality  is  injured.  It 
is  difficult  to  avoid  the  occurrence  of  such  fermentation  after  rains 
have  prevented  delivery  for  several  days.  Much  heated  fruit  was  seen 
near  the  end  of  the  1923  season. 

Lye  Treatment — Lye  treatment  is  for  the  purpose  of  removing  most 
of  the  bitterness  and  rendering  the  skin  of  the  olives  permeable  to  brine 
and  fermentation  organisms.  In  all  of  the  factories  visited,  concrete 
or  brick  vats  lined  with  cement  are  used  as  containers  for  the  olives 
during  the  lye  and  washing  processes.  These  vats  are  about  as  wide  as 
those  used  in  California,  but  are  shorter  and  about  twice  as  deep  as 
ours.  Iron  pipe  lines  supply  each  vat  with  lye  solution  and  water. 
See  fig.  15. 


18 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Granular  soda  lye  (sodium  hydroxide),  of  Spanish  manufacture  in 
most  cases,  is  used  in  preparing  the  lye  solution.  In  one  factory  a 
concentrated  solution  is  made  in  a  sheet-iron  tank,  and  this  solution  is 
diluted  to  the  desired  strength  in  a  vat  below  the  floor  level.  From  this 
vat  it  is  pumped  to  the  pickling  vats. 

The  strength  of  the  lye  is  varied  according  to  the  maturity  and 
variety  of  the  olives,  the  temperature,  and  other  factors.  According 
to  Gracey,  the  average  concentration  for  Sevillano  olives  is  2y2° 
Baume  (10°  salometer)  and  for  Manzanillos  3°  Baume  (12°  salo- 
meter). A  sample  from  the  Barea  factory  analyzed  by  the  writer 
contained  1.9%  sodium  hydroxide,  approximately  2.8°  Baume  (7*4° 
salometer). 


Fig.  12. — Donkey  with  side  bags  of  olives.     Near  Seville. 

The  olives  are  completely  covered  with  the  solution,  and  are  pre- 
vented from  floating  above  the  surface  by  means  of  floats  (usually  of 
heavy  grass  matting) .  They  are  stirred  occasionally  and  lye  penetra- 
tion is  carefully  observed  by  frequently  cutting  samples  to  the  pit  with 
a  knife.  The  solution  changes  the  flesh  to  a  yellowish  green  color 
to  the  depth  of  penetration.  The  lye  is  allowed  to  penetrate  about  two- 
thirds  of  the  way  to  the  pit — some  of  the  fruit  will  be  penetrated  only 
one-half  way  and  some  completely  to  the  pit,  but  the  average  penetra- 
tion is  about  two-thirds  of  the  way.  No  definite  period  of  time  can  be 
given  for  the  duration  of  lye  treatment.  According  to  those  inter- 
viewed, the  time  varies  from  4  to  8  hours,  but  the  depth  of  penetra- 
tion and  not  the  length  of  treatment  is  the  important  consideration. 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES 


19 


Too  deep  penetration  will  destroy  all  of  the  bitterness,  bleach  the  olives, 
and  may  result  in  softening".  .  If  penetration  is  not  deep  enough,  the 
olives  will  remain  too  bitter,  even  after  fermentation.  Untreated  flesh 
and  bitterness  are  necessary,  in  order  that  fermentation  will  be  normal 
and  the  finished  pickle  will  have  the  proper  flavor,  color,  and  texture. 


Fig.  13. — Carts  used  for  hauling  olives.     Seville 


Fig.  14. — Transporting  olives  by  rail  to  pickling  factory.     Near  Seville. 


In  most  factories  the  spent  lye  is  discarded,  but  in  at  least  one 
large  factory,  that  of  Don  Diego  Gomez,  the  used  lye  solution  is  forti- 
fied by  the  addition  of  a  concentrated  lye  solution  and  used  a  second 
time. 


20 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Washing. — The  excess  of  lye  is  washed  from  the  olives  as  in  Cali- 
fornia by  several  applications  of  cold  water  in  which  the  olives  stand. 
They  are  stirred  occasionally  to  hasten  and  equalize  leaching  of  the 
solution  from  the  fruit.  The  washing  period  is  much  shorter  than  in 
California,  usually  not  more  than  24  hours — the  total  time  required  for 
lye  treatment  and  washing  often  being  less  than  24  hours. 

The  olives  still  contain  some  lye  when  they  are  removed  from  the 
vats.  In  all  cases  where  the  washed  olives  were  cut  and  tested  with 
dilute  phenolphthalein  solution,  a  strong  reaction  for  free  lye  was 
obtained.  Olives  from  four  different  plants  were  tested  in  this  man- 
ner.    It  seems  very  probable  that  much  of  the  trouble  encountered  in 


Fig.  15. — Pickling  vats  in  Barea  factory.     Seville. 

Seville  factories  with  improper  lactic  acid  fermentation  and  putre- 
faction, may  be  due  to  insufficient  removal  of  lye  from  the  fruit  tissue, 
and  the  writer  would  advise  washing  until  all  or  nearly  all  of  lye- 
treated  flesh  is  free  from  lye. 

Fermentation. — The  fermentation  process  is  responsible  for  the 
special  flavor  of  Spanish  green  olives.  The  washed  olives  are  placed 
in  hogsheads  (puncheons  or  "bocoys")  of  about  168  gallons  capacity. 
Each  "bocoy"  holds  about  1016  pounds  (10%  "fanegas")  of  olives 
and  about  800  pounds  of  brine  for  covering  the  olives. 

To  fill  the  "bocoy"  the  upper  hoops  are  loosened,  one  head  removed, 
and  the  washed  olives  added  to  the  level  of  the  inner  side  of  the  head. 
The  head  is  then  replaced  and  the  hoops  tightened. 

The  bocoys  are  rolled  into  the  fermentation  yard,  and  usually 
placed  on  wooden  skids  to  elevate  them  above  the  wet  ground.     (Figs. 


Circular  278]      OLIVE  PICKLING  IN   MEDITERRANEAN    COUNTRIES 


21 


16  and  18  illustrate  a  typical  yard  and  style  of  cask  used.)  They  are 
then  filled  with  a  heavy  brine,  10  or  11°  Baume  (40  to  44°  salometer)  — 
two  samples  from  different  factories  were  found  to  be  11°  Baume  at 
room  temperature  (about  60°  F.). 

The  pickler  desires  bright,  warm  sunshiny  weather,  in  order  to 
hasten  fermentation  by  increasing  the  temperature  of  the  olives  and 
brine.  The  weather  in  Seville  in  September  and  October  is  much 
warmer  than  in  California  during  our  olive  pickling  season  in  late 
October  and  early  November ;  hence,  it  might  be  necessary  in  this  state 
to  store  the  barrels  in  a  warm  room  in  order  to  promote  fermentation. 

During  fermentation  the  salt  content  of  the  brine  decreas3S  because 
of  its  dilution  by  the  water  of  the  fruit ;  the  acidity  of  the  brine 


Fig.  16. — Olmeda  Company's  pickling  yard.     San  Jnan,  near  Seville. 

increases  rapidly  by  the  formation  of  organic  acids,  principally  lactic, 
by  bacteria ;  froth  appears  at  the  bung  of  the  barrel  and  gas  is  given 
off  until  the  fermentation  is  complete;  while  the  flesh  "cures"  com- 
pletely'to  "file  pit  and  acquires  a  yellowish  green  color,  a  characteristic 
aromati'cl  flavor,  and  a  sour  taste.  The  flesh  also  absorbs  salt  and 
becomes  tough. 

Fermentation  in  unusually  warm  weather,  as  in  September  and 
October,  1923,  may  be  completed  in  one  month ;  in  cool  weather  it  may 
require  three  months  or  longer.  If  fermentation  is  not  complete  a1  the 
time  of . shipment  over-seas,  it  will  commence  again  when  the  tempera- 
ture becomes  favorable,  causing  bursting  of  bottles  or  blowing  out  of 
the  corks.  Several  weeks  before  the  olives  are  to  be  shipped  careful 
picklers  take:small  samples  which  they  bottle,  cork  and  incubate  al 
about  90°  F.  to  determine  whether  gas  formation  will  occur. 


22 


UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 


During  active  fermentation  a  considerable  quantity  of  brine  is  lost 
by  frothing  and  as  it  is  necessary  to  keep  the  barrels  full  to  prevent 
growth  of  mycoderma  (white  film  yeast)  the  barrels  must  be  filled  to 
overflowing  frequently  during  this  period  by  addition  of  fresh  brine 
of  10  to  11°  Baume.    See  fig.  17. 

Analyses  which  the  writer  was  able  to  make  of  samples  of  brine 
from  ' '  bocoys ' '  of  olives  at  various  stages  of  the  curing  process  give  an 
idea  of  the  chemical  changes  taking  place  in  the  brine  during  the 
fermentation. 


Pig.  17. — Containers  for  brine  used  in  filling  barrels  to  replace  brine  lost 
during  fermentation.     Seville. 


TABLE  2 

Changes 

Occurring  in  Brine 

During  Fermentation 

(Sevillano  Olives) 

Seville,  1923 

Sample 

No.  of  days  on 
olives 

Acidity  as  per  cent 
lactic  acid 

Salt 

—per  cent  by 
titration 

1 

Less  than  2  hours           Slightly  alkaline 

11.2 

2 

2 

.045 

8.4 

3 

12 

.405 

5.76 

4* 

17 

.18 



5 

22 

.765 

5.26 

6 

25 

.918 

5.09 

7 

30 

.81 



8 

365 
(more  or  less) 

.855 

.... 

*  Sample  No.  4  was  slimy — evidently  an  unsuitable  fermentation  was  taking 
place. 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES 


23 


According  to  Mr.  L.  Boucher  of  the  University  of  Seville,  the  salt 
concentration  frequently  decreases  to  4.5  per  cent.  The  Baume  hydro- 
meter will  indicate  considerably  more  salt  than  this,  because  it  is 
affected  by  soluble  materials  extracted  by  the  brine  from  the  fruit. 
Chemical  analysis  is  the  only  reliable  method  of  determining  salt  in 
such  solutions.  However,  it  is  not  necessary  that  salt  determinations 
of  the  fermented  brine  be  made;  the  essential  condition  to  be  deter- 
mined is  the  percentage  of  acid  present  after  fermentation.  If  this  is 
very  low,  the  olives  will  spoil. 


Fig.  18. — A  farmer's  pickling  yard.     Italica,  near  Seville. 


Grading,  Sorting,  and  Shipping. — When  the  fermentation  is  com- 
plete, the  barrels  are  completely  filled,  sealed,  and  stored  until  needed 
for  shipment.    Properly  fermented  olives  will  keep  at  least  two  years. 

The  shipping  and  packing  season  extends  throughout  the  year  but 
is  most  active  during  winter  and  spring. 

Before  shipment  in  bulk  to  the  United  States  or  other  foreign 
market,  the  olives  are  removed  from  the  ' '  bocoys ' '  after  first  drawing 
off  some  of  the  brine  and  the  removal  of  one  head.  They  are  graded 
roughly  by  hand-operated  screens  into  three  sizes.  These  are  again 
carefully  size  graded  by  hand  and  sorted  for  quality.  Three  quality 
grades  are  made:  First  Quality,  Second  Quality,  and  Culls.  Very 
little  of  the  Second  Quality  and  none  of  the  culls  are  exported.  Not 
more  than  10  per  cent  of  the  First  Quality  should  show  slight  imperfec- 
tions ;  nearly  all  of  the  olives  of  the  Second  Quality  show  some  sort  of 


24  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

imperfections;  while  the  Culls  are  broken,  insect-injured,  and  other- 
wise badly  blemished  specimens.  The  Culls  and  most  of  the  Second 
Quality  are  sold  locally. 

The  size  grades,  according  to  W.  T.  Gracey,  are  reported  as 
' '  number  of  pairs  of  olives  per  half  kilo, "  as  ' '  olives  per  kilogram, ' ' 
and  as  "olives  per  pound."  The  usual  designation  is  number  per 
kilogram  or  per  "kilo."  The  range,  according  to  W.  T.  Gracey,  is 
60-70  per  kilogram  to  400-450  per  kilogram.  The  usual  grades  for 
Sevillanos  are  Large  70-80  to  90-100,  Medium  100-110  to  130-140, 
and  Small  140-200  per  kilogram.  The  range  for  Manzanillos  is  180- 
200  to  380-400  per  kilogram.    One  kilogram  equals  2.2  pounds. 

After  grading  the  olives  are  replaced  in  the  barrels  used  during 
fermentation,  and  the  original  brine  is  returned  to  them.  The  barrels 
are  headed  up  again;  any  brine  lost  during  sorting  is  replaced  by 
fresh  brine  of  10°  Baume;  and  the  barrels  sealed.  They  are  shipped 
by  boat  from  the  quay  on  the  Guadalquivir  River,  which  is  at  tide  level. 

Packing  in  Glass  and  Tin. — A  considerable  quantity  of  olives  is 
packed  in  glass  and  tin  for  export.  In  the  United  States  most  of  the 
olives  are  packed  in  glass  by  the  importers. 

For  packing  in  tin  cans  the  Manzanillo  variety  is  used.  These  are 
graded  for  size;  sorted;  filled  into  lithographed  tin  cans  holding  from 
one-half  to  five  kilograms ;  the  original  brine  is  added ;  and  the  cans 
are  sealed  with  solder.  They  are  not  sterilized  but  are  simply  packed 
in  cases  and  shipped  without  further  treatment.  The  cans  often  swell 
slightly  from  gas  formation,  but  it  is  said  that  loss  from  leaking  or 
bursting  of  the  cans  is  slight.  These  olives  are  shipped  to  Latin- 
American  countries.  Recently  a  satisfactory  process  of  canning  green 
olives  has  been  developed  in  the  eastern  United  States,  according  to 
Fitzgerald  of  the  National  Canners'  Association.  This  consists  in 
filling  the  olives  into  cans,  brining,  exhausting  heavily  in  live  steam 
and  sealing.     No  further  heating  is  required. 

For  the  fancy  glass-packed  fruit  the  olives  are  placed  in  the  jars  by 
means  of  a  long  slender  wooden  stick,  or  by  long  wooden  or  bronze 
tweezers.  A  loose  pack  is  also  made  both  in  Spain  and  the  United 
States  by  dropping  the  olives  into  the  jars  and  tapping  the  jars  lightly 
against  the  table  to  settle  the  olives. 

The  olives,  after  packing  by  either  method,  are  rinsed  by  immersing 
in  a  tank  of  water  and  inverting  to  drain.  This  is  to  remove  bacterial 
cells,  and  other  small  particles  adhering  to  the  olives,  in  order  to  reduce 
the  amount  of  sediment  formed  in  the  bottom  of  the  bottle  or  on  the 
olives  during  storage.  The  bottles  are  then  filled  with  freshly  pre- 
pared brine  of  about  9°  Baume.    The  bottles  in  Spain  are  sealed  with 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES  25 

long  corks  forced  tightly  into  the  necks.  In  the  United  States  vacuum 
sealed  jars  are  also  used.  The  olives  must  be  completely  fermented 
before  packing  or  gas  will  be  formed  and  the  corks  forced  from  the 
bottles  or  the  bottles  broken.  Slight  gas  pressure  may  do  no  harm. 
Pitting  and  Stuffing. — Stuffed  Manzanillo  olives  are  much  in 
demand  in  the  United  States.  The  stuffing  is  done  in  the  Spanish 
factories,  and  the  olives  are  then  barreled  for  export  to  the  United 
States.    The  graded  and  sorted  olives  are  first  pitted  by  a  small  plunger 


Fig.  19. — Olive  pitter.     Seville. 

operated  by  a  hand  lever.  See  fig.  19.  Each  olive  must  be  placed  on 
end  and  carefully  pitted  to  avoid  undue  tearing  of  the  flesh  and  to 
insure  a  uniform  appearance.  Sevilla.no  olives  are  difficult  to  pit, 
because  they  possess  rough  pits  which  cause  a  large  percentage  of  the 
olives  to  break  or  tear  excessively. 

Small  strips  of  canned  pimiento  from  Valencia  or  Logroiio,  Spain, 
are  folded  and  stuffed  into  the  pitted  olives  by  hand.  These  olives  are 
then  packed  in  barrels  holding  about  48  gallons ;  these  are  filled  with 
fresh  brine  (presumably  10°  Baume)  and  allowed  to  stand  in  the  sun 
and  with  the  bungs  open  until  fermentation  of  the  pimiento  flesh  is 
complete — a  month  or  longer  is  required.    Unless  this  is  done,  f  ermen- 


26  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 

tation  and  gas  formation  will  occur  during  shipment  or  after  packing 
later  in  bottles.  The  stuffed  olives  after  arrival  at  American  packing 
houses  are  packed  in  glass  as  described  above  for  the  whole  olives. 

Spoilage  and  Deterioration. — The  principal  form  of  spoilage  is 
known  as  "Zapatera."  This  is  a  bacterial  decomposition  resulting  in 
such  marked  changes  in  flavor  and  odor  that  the  olives  are  rendered 
unmerchantable.  It  usually  does  not  become  evident  until  the  olives 
have  been  stored  for  several  months  or  a  year  after  curing.  A  promi- 
nent olive  packer  of  Seville  states  that  olives  which  have  heated  in  the 
baskets  or  other  containers  before  pickling  are  much  more  susceptible 
to  this  disease  than  are  those  pickled  promptly  after  picking.  He  also 
states  that  the  disease  is  very  infectious  and  may  be  carried  from  one 
barrel  to  another  in  brine  adhering  to  the  fingers  or  sampler. 

This  trouble  is  probably  due  in  part  to  defective  lactic  acid  fermen- 
tation and  its  occurrence  might  be  greatly  reduced  in  frequency  if  the 
brines  in  each  of  the  fermentation  casks  were  inoculated,  at  the  time  of 
filling,  with  3  or  4  gallons  of  brine  from  a  cask  known  to  have  under- 
gone proper  fermentation,  or  if  about  0.1  to  0.2  per  cent  of  lactic  acid 
were  added  to  the  brine  before  fermentation.  The  practice  of  leaving 
a  considerable  amount  of  free  lye  in  the  olives  undoubtedly  discourager 
the  development  of  lactic  acid  bacteria  and  may  favor  the  growth  of 
bacteria  responsible  for  "zapatera. "  The  free  lye  should  be  removed 
by  more  thorough  washing.  Acidification  of  the  brine  used  in  packing 
the  cured  olives  in  glass  might  also  be  advisable,  since  it  would  dis- 
courage the  growth  of  putrefactive  organisms. 

Slimy  or  "ropy"  brines  are  common  in  many  pickling  yards,  par- 
ticularly during  the  first  month  of  fermentation.  The  sliminess  dis- 
appears as  the  fermentation  progresses ;  nevertheless,  it  is  evidence  of 
growth  of  undesirable  organisms  and  should  be  avoided,  if  possible. 
The  means  suggested  above  for  control  of  zapatera  might  be  effective 
in  these  cases. 

A  white  deposit  is  frequently  found  on  the  olives  and  the  bottom 
of  jars  or  bottles  of  green  olives.  Microscopical  examination  proves 
that  in  some  cases  the  deposit  consists  of  bacteria.  These  bacteria  are 
in  part  those  left  by  insufficient  washing  of  the  olives  at  the  time  of 
packing  and  in  part  those  due  to  growth  of  bacteria  in  the  container. 
In  other  samples  the  deposit  does  not  consist  of  bacteria  but  of  amor- 
phous particles.  These  may  be  particles  of  insoluble  soaps  formed  by 
reaction  between  small  amounts  of  soluble  sodium  soaps  from  the  olive 
and  calcium  salts  in  the  brine.  Salt  and  water  used  for  preparing 
green  olives  should  be  as  free  as  possible  from  calcium  and  magnesium 
salts. 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES  27 

The  growth  of  film  yeasts  on  the  brine  during  storage  must  be 
prevented  by  keeping  the  container  full  and  sealed. 

Casts. — It  was  difficult  to  obtain  estimates  of  cost  of  producing  green 
olive  pickles  in  Spain.  However,  certain  costs  are  well  known.  The 
price  paid  for  olives  in  the  1923  season  varied  from  about  10  pesetas 
the  fanega  for  oil  stock  to  a  maximum  of  about  30  pesetas  the  fanega 
for  pickling  fruit.  One  packer  placed  the  average  price  range  for 
pickling  fruit  at  20-25  pesetas  the  fanega.  "With  the  peseta  at  14 
cents  American,  and  the  fanegas  96.8  pounds,  this  would  represent 
prices  of  about  $57.75  to  $72.30  a  ton  for  the  average  range  and  about 
$86.80  a  ton  as  the  maximum  price.  These  prices  are  for  fruit  of 
pickling  size  carefully  selected  for  size  and  sorted  for  quality  before 
delivery.  Wages  for  ordinary  labor,  according  to  the  vice-consul, 
were  in  1923,  for  men,  6  pesetas  (84  cents)  and  for  women  and  children, 
about  3  pesetas  (42  cents).  Those  employed  at  piece  work  in  packing 
olives  (skilled  labor)  earn  about  10  pesetas  a  day,  according  to  one 
Seville  packer.  Salt  at  one  factory  costs  less  than  $4.00  (American) 
a  ton.  W.  T.  Gracey  placed  the  cost  of  pickling  at  2  pesetas  the  fanega 
in  1918,  or  $8.00  a  ton.  This  included  cost  of  labor,  lye,  salt,  and  water 
but  not  cost  of  sorting,  which  is  about  $4.00  a  ton. 

In  1922,  according  to  W.  C.  Burdette,  the  price  for  green  pickled 
olives  (Queens)  opened  at  45  pesetas  a  fanega,  f.o.b.  Seville — a  normal 
price  (equivalent  to  about  $130  a  ton).  Because  of  scarcity  of  fruit 
and  keen  competition  among  American  importers,  the  price  rose  to 
100  pesetas  a  fanega  at  the  end  of  the  season  in  June.  This  price  is 
equivalent  to  about  $300  a  ton,  f.o.b.  Seville,  and  is  considered  unusu- 
ally high.  Yet  this  is  lower  than  the  price  often  paid  by  the  picklers  in 
California  for  the  fresh  Sevillano  olives.  Evidently  Spanish  growers 
and  packers  can,  if  forced  by  competition,  place  green  pickled  olives 
on  board  ship  at  Seville  at  less  than  one-half  the  price  of  the  fresh 
fruit  in  California. 

B.    FRENCH    PROCESS 

Several  methods  are  in  common  use  for  preparing  olives  for  sale  in 
France,  but  for  pickling  olives  for  export  one  method  is  used  almost 
to  the  exclusion  of  others  and  will  be  designated  ' '  the  French  Process. ' ' 
This  process  was  observed  in  several  factories  in  Nimes.  According 
to  J.  Bonnet,*  France  has  an  area  of  120,000  hectares  (296,400  acres) 
compared  with  Spain's  1,600,000  hectares  (3,952,000  acres). 

Harvesting. — In  the  factories  in  Nimes  both  green  and  ripe  pickles 
are  prepared.     As  in  Spain,  the  green  fruit  is  harvested  while  still 

*  Director  of  the  French  Olive  Service. 


28  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

green  to  straw  yellow,  but  after  it  has  reached  full  size.  The  ripe 
fruit  is  taken  after  it  has  acquired  a  cherry  red  to  black  color  but 
before  it  has  become  too  soft.    Bruising  must  be  avoided. 

Lye  Treatment. — The  lye  treatment  is  more  severe  than  in  Seville 
or  California.  J.  Bonnet  of  the  Ministry  of  Agriculture  informed  the 
writer  that  the  solution  used  for  green  olives  varies  from  3  to  5° 
Baume  (12-20°  salometer)  according  to  the  variety.  This  solution  is 
applied  in  concrete  vats  in  the  Nimes  factories  and  allowed  to  remain 
until  the  pit  of  the  olive  "comes  free"  from  the  flesh.  Mr.  Bonnet 
states  that  normally  12  hours  or  longer  is  required.  The  ripe  olives 
receive  somewhat  weaker  solutions:  2  to  3°  Baume  (8-12°  salometer). 

A.  Rolet  of  Antibes,  France,  recommends  for  the  Verdale  olives  a 
solution  of  6°  Baume  and  for  the  other  varieties  3.5  to  5°  Baume. 

Washing. — Great  care  is  taken  to  avoid  exposure  of  the  green  olives 
to  the  air  in  order  to  prevent  browning.  Fresh  water  is  applied  and 
changed  two  or  three  times  daily  until  the  lye  is  completely  removed. 

Brine  Treatment. — The  olives  are  not  permitted  to  ferment  and 
must  therefore  be  preserved  in  a  strong  brine.  In  order  to  prevent 
shriveling,  the  concentration  of  salt  is  increased  progressively  at 
intervals  of  two  or  three  days  each  as  follows:  3°,  5°,  7%°,  and  10° 
Baume  salt  solution,  and  finally  in  a  solution  of  12°  Baume.  This 
last  solution  is  changed  occasionally  to  avoid  mold  and  bacterial  decom- 
position.   Wooden  floats  are  used  to  submerge  the  olives. 

Packaging. — Wooden  barrels  are  used  for  most  of  the  fruit,  which 
is  shipped  in  fresh  brine  of  12°  Baume  (48°  salometer). 

Much  of  the  fruit  is  packed  in  glass  in  fresh  brine  of  10  to  12° 
Baume.  Salt-cured  anchovy  meat  is  often  used  for  stuffing  the  pitted 
olives.  In  a  large  cannery  near  Paris  in  which  the  packing  of  French 
cured  olives  was  observed,  the  filled  jars  were  not  sterilized  by  heat — 
the  strong  brine  was  relied  upon  to  prevent  spoiling. 

1923  Price  for  Fresh  Olives. — According  to  Bonnet,  the  price  for 
olives  for  pickling  purposes  was  2  francs  a  kilogram  in  1923 — this  is 
approximately  4.6  cents  per  pound  at  the  rate  of  exchange  prevailing 
at  that  time — or  about  $92.00  per  ton.  Oil  olives  sold  at  about  one-half 
this  price. 

C.    SALT    CUEING    OF    OLIVES 

For  domestic  consumption  in  Spain  and  Italy  most  olives  are  cured 
without  the  use  of  lye.  There  are  two  methods  of  applying  the  salt : 
dry,  and  in  the  form  of  a  strong  brine.  The  dry  application  is 
probably  the  more  important. 


Circular  278]     olive  pickling  in  mediterranean  COUNTRIES  29 

The  "Greek"  Process. — According-  to  olive  men  interviewed  in 
France  and  Italy  there  are  several  important  processes  in  use  in 
Greece,  but  the  most  important  of  these  and  the  one  in  common  use 
in  northern  Africa  and  Italy  to  produce  ' '  Greek  style ' '  pickled  olives 
is  the  following : 

"Dead  ripe"  olives  of  large  size  and  black  color  are  used.  These 
are  placed  in  a  barrel  with  alternate  layers  of  salt — one  pound  of  salt 
to  9  pounds  of  olives.  The  barrel  is  filled  completely,  headed  up,  and 
sealed.  It  is  placed  on  its  side  and  rolled  every  three  or  four  days  for 
the  first  month  and  once  every  fifteen  days  thereafter  in  order  to  pre- 
vent molding  and  the  sticking  of  the  olives  together.  The  salt  by 
osmosis  draws  juice  from  the  olives  and  forms  a  heavy  brine.  The 
bitterness  gradually  decreases  and  at  the  end  of  two  months  the  olives 
are  usually  ready  for  consumption.  Barrels  of  50  gallons  are 
recommended. 

The  retailer  usually  refreshes  the  olives  in  dilute  brine  for  a  day 
or  two  before  placing  them  on  sale.  He  may  add  herbs  and  other 
flavoring  materials,  such  as  bay  leaves,  fennel,  sliced  lemon,  and  sweet 
peppers.  Usually  the  fruit  as  seen  in  southern  European  markets 
is  drained  free  of  brine  and  placed  in  little  heaps  on  the  market  tables 
or  in  shallow  baskets. 

In  Spain. — For  domestic  consumption  large  quantities  of  ripe 
olives  are  cured  by  storage  in  barrels  or  casks  in  a  brine  of  10°  Baume 
(40°  salometer).  After  about  one  year's  storage  the  fruit  is  sold. 
It  possesses  a  pleasing  fermented  taste  somewhat  like  that  of  the 
Spanish  green  cured  olives.  The  process  is  to  pack  the  fruit  in  barrels ; 
head  up  the  barrels;  fill  with  10°  Baume  (40°  salometer)  brine  and 
leave  with  bung  open.  The  barrel  is  kept  full  to  overflowing  with 
brine  of  10°  Baume  until  fermentation  ceases;  then  sealed  and  stored 
until  edible — about  one  year.  The  product  is  plump,  slightly  bleached 
in  color,  and  distinctly  but  not  disagreeably  bitter. 

Dry  Salt  Cure. — This  was  not  seen,  although  dry  salt-cured  olives 
were  observed  on  sale.  Probably  the  process  used  was  similar  to  that 
described  by  Caldis,*  in  which  the  olives  are  placed  in  baskets  with 
alternate  layers  of  rock  salt  and  allowed  to  stand  until  edible.  The 
brine  drains  through  the  basket  as  rapidly  as  it  forms.  These  olives 
are  often  preserved  in  olive  oil  or  soaked  in  oil  before  serving. 


*  Caldis,   A.      Curing  Olives   in   Greece.     Proceedings   of   Olive    Processors' 
Conference,  Berkeley,   1923,  p.  29. 


30  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


D.    MISCELLANEOUS    PEOCESSES 

Water  Curing. — This  is  one  of  the  favorite  methods  of  removing 
the  bitterness  in  the  Seville  district.  It  is  also  used  in  France  and 
Italy. 

In  Spain  the  olives  are  often  slit  lengthwise  to  the  pit  in  three  or 
four  places ;  this  is  done  by  hand  or  by  means  of  three  or  four  sharp 
blades  mounted  around  a  hole  in  a  board.  In  the  latter  case  the  olive 
is  slit  by  forcing  it  through  the  hole  past  the  cutting  surfaces.  Slitting 
facilitates  extraction  of  the  bitterness. 

A  more  common  method  is  to  crush  the  olives  lightly  either  with  a 
wooden  mallet  or  between  wooden  rollers  so  adjusted  that  the  flesh 
of  the  olive  is  broken  without  breaking  the  pit. 

The  slit  or  crushed  olives  are  placed  in  tubs  or  open  barrels  of 
water,  which  is  changed  three  or  four  times  daily  until  the  fruit  is 
edible.  The  writer  was  told  by  one  pickler  that  washing  for  about  two 
weeks  was  required. 

Flavoring  and  Preserving. — If  the  olives  are  to  be  consumed  at 
once,  a  light  brine  acidified  with  vinegar  is  added.  Sliced  sweet 
peppers,  garlic,  fennel,  whole  pepper  seed,  whole  mustard  seed,  bay 
leaves,  and  other  spices  are  added  in  most  cases.  After  standing 
several  days,  the  olives  are  ready  for  sale.  Their  life  is  short — spoiling 
soon  begins  unless  a  strong  brine  of  10  to  12°  Baume  or  a  high  concen- 
tration of  vinegar  is  used.  This  type  of  pickle  was  purchased  in 
Seville  in  November,  1923,  at  retail  for  7  cents  a  pound.  The  flavor 
was  pleasing.  This  pickle  is  a  favorite  with  Spanish  consumers. 
Pickles  of  this  type  were  found  to  be  common  also  in  Palermo  and 
Messina  in  Sicily,  in  Florence  and  Lucca  in  Italy,  and  in  Marseilles 
in  France. 

Often,  olives  cured  by  the  Spanish  green  process  (usually  culls  or 
seconds  from  the  packing  houses)  are  broken  after  pickling  and  are 
sold  in  a  vinegar  brine  flavored  with  garlic,  peppers,  and  spices. 

While  these  products  would  probably  not  be  practicable  in  America 
it  is  probable  that  the  following  modification  would  have  possibilities. 
Pickle  the  green  fruit  by  one  lye,  no  exposure  process.  Crush  lightly. 
Can  in  4°  Baume  brine  containing  vinegar,  sliced  sweet  peppers,  bay 
leaves,  fennel,  and  other  suitable  spices,  and  sterilize  for  sale  to  the 
Latin- American  trade. 

Another  product  of  a  type  somewhat  similar  to  the  crushed  olives  is 
made  in  the  United  States  from  the  culls  from  imported  Spanish  green 
olives.     The  olives  are  pitted  and  ground  coarsely  for  use  in  sand- 


CIRCULAR  278]       OLIVE   PICKLING    IN    MEDITERRANEAN    COUNTRIES  31 

wiches  and  as  a  relish.  This  product  is  excellent  without  mixing  with 
other  materials,  but  is  improved  by  addition  of  pimiento.  If  California 
olive  packers  are  to  seriously  consider  the  preparation  and  sale  of 
small  olives  in  the  form  of  a  relish  or  butter  it  is  advised  that  experi- 
ments be  made  in  which  the  fruit  is  first  pickled  by  the  Spanish  green 
olive  process.  The  olives  might  then  be  made  into  a  rather  coarse 
"butter"  or  sandwich  filler  by  means  of  a  tomato  pulper  equipped 
with  a  very  coarse  screen  or  by  other  suitable  mechanical  device.  If 
pimiento  is  added  it  would  be  necessary  to  sterilize  the  product.  How- 
ever, on  account  of  the  high  acidity  of  the  green  pickles  sterilization 
should  not  be  difficult.  A  satisfactory  imitation  of  the  green  oliv 
butter  has  been  prepared  in  the  Fruit  Products  Laboratory  of  the  Col- 
College  of  Agriculture  by  first  pickling  the  olives  by  the  ripe  process ; 
pitting;  grinding  coarsely;  adding  10%  by  weight  each  of  ground 
pimiento  and  horseradish  and  20%  of  ground,  sour  cucumber  pickles. 
This  product  is  sour  but  the  olive  flavor  predominates.  It  is  not 
injured  in  flavor  by  sterilization  at  240°  Fahrenheit  for  40  minutes. 

Dried  Olives. — A  popular  olive  "pickle"  on  the  Italian  table  is  the 
dried  olive.  A  recipe  given  by  a  cook  at  Castel  Ruggiero,  near 
Florence,  was  as  follows :  '  *  Use  ripe  olives.  Dip  in  boiling  water  2  or 
3  minutes.  Dry  on  cloth  in  the  sun  or,  if  the  weather  is  unfavorable, 
in  the  oven.    Store  in  baskets  in  a  dry  place. ' ' 

A  variation  consists  in  dipping  in  boiling  water ;  soaking  in  brine 
a  day  or  two ;  and  then  drying. 


SUMMARY  AND   CONCLUSIONS 

1.  Cultural  Methods. — The  methods  of  growing  of  olives  for  pick- 
ling purposes  in  Spain,  France  and  Italy  are  distinctly  different  from 
those  in  use  in  California.  In  Europe  the  trees  are  pruned  more 
severely  and  fertilized  more  regularly  than  in  California.  Irrigation 
even  in  semi-arid  localities  is  much  less  common  than  in  California. 

California  growers  should  test  the  southern  European  methods  of 
pruning  and  fertilization  in  order  to  ascertain  whether  they  would 
induce  more  regular  bearing  than  exists  at  present.  More  European 
olive  sections  could  undoubtedly  use  irrigation  to  advantage. 

2.  Olive  Fly. — The  olive  fly  is  a  serious  menace  to  the  olive  industry 
of  southern  Europe.  All  reasonable  precautions  should  be  taken  to 
exclude  it  from  California,  Satisfactory  control  by  sprays  or  other 
means  has  not  been  perfected  although  spraying  frequently  with  a 


32  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

sweet  arsenical  spray  has  given  fair  control  in  Italy.  Olives  in  southern 
Spain  to  be  used  for  pickling  are  harvested  before  full  maturity  in 
order  to  avoid  damage  by  the  olive  fly. 

3.  Varieties  for  Pickling. — Several  European  varieties  not  now 
grown  commercially  in  California  might  prove  valuable  in  this  state 
for  ripe  pickling.    These  are : 

(a)   Spanish  varieties  :  Murcal,  Cordovi,  Madrileno,  and  Rapasayo  ; 

( o )   French  varieties :  Amellau,  Picholine  and  Lucques ;  and 

(c)   Italian  varieties:  Santa  Catarina,  Castriciano  and  the  Ago- 

stino. 

Trees  of  the  Santa  Catarina  and  the  Lucques  are  growing  at  the 

University  Farm  or  elsewhere  in  the  state.  Attempts  are  being  made 

to  introduce  grafting  wood  of  the  other  varieties. 

4.  Spanish  Green  Olives. — The  Spanish  green  olive  pickling  pro- 
cess was  carefully  studied  in  the  factories  in  and  near  Seville  and  is 
described  fully  in  this  publication.  It  is  believed  that  California 
picklers  could  utilize  a  considerable  portion  of  the  crop  of  some  varie- 
ties for  green  pickling.  It  might  be  necessary  to  modify  the  process 
to  suit  our  temperature  and  other  conditions.  Green  olives  in  the 
eastern  United  States  are  made  into  a  relish  or  sandwich  filler  by 
coarsely  grinding  the  pitted  olives.  This  is  very  popular.  Perhaps  our 
small  olives  could  be  pickled  by  the  green  process;  coarsely  pulped 
and  pitted  mechanically  to  give  such  a  relish ;  or  the  ripe  pickled  Oliver 
similarly  pulped  and  flavored  to  give  a  relish  with  a  flavor  similar  to 
that  made  from  the  green  olives. 

5.  French  Process. — The  French  process  is  essentially  the  old 
California  process  in  which  the  olives  are  treated  with  one  lye  solution 
only,  washed  free  of  lye  and  preserved  in  a  very  strong  brine.  Its  use 
probably  should  not  be  revived  in  this  state. 

6.  Greek  Process. — The  Greek  process  as  applied  in  southern 
Europe  and  northern  Africa  consists  in  curing  the  olives  in  sealed 
barrels.  Ten  per  cent  salt  is  mixed  with  the  olives.  This  extracts 
juice  from  the  fruit  and  forms  a  heavy  brine.  This  process  may  be  an 
improvement  upon  that  in  use  in  California  for  preparing  salt-cured 
olives. 

7.  Other  Processes. — Olives  are  slit  or  crushed,  leached  free  of 
bitterness  in  water  and  then  stored  in  dilute  vinegar  or  brine  flavored 
with  spices  and  sweet  peppers.  These  are  popular  for  local  sale  in 
Europe.  Perhaps  spiced,  crushed,  canned  and  sterilized  pickled  Oliver 
could  be  sold  in  America  to  people  of  southern  European  origin. 

Dried  olives  are  also  common  and  popular  as  are  also  those  cured 
in  10°  Baume  brine  without  the  addition  of  lye. 


Circular  278]     olive  pickling  in  mediterranean  COUNTRIES  33 


SELECTED  REFERENCES 

Spanish,  French  and  Italian  publications  on  Olive  Culture,  Oil  Making,  and 
Pickling  are  very  numerous;  a  complete  list  would  be  of  little  value  to  California 
growers  and  packers;  therefore,  a  few  selected  references  only  are  given. 

Spanish  Green  Olives — 

1.  Wilbur   T.   Gracey.     Olive    Growing  in   Spain.      Special   Consular   Report 

No.  79.  34  pages.  1918.  Obtainable  for  5  cents  in  coin  from  the 
Superintendent  of  Documents,  Government  Printing  Office, 
Washington,  D.  C. 

2.  El  Aceite  de  Oliva.     Resumen  hecho  por  la  Junta  Consultiva  Agronomica. 

Madrid,  1923.  Obtainable  from  Ministerio  de  Fomento,  Madrid, 
Spain.  Published  by  Hijos  de  M.  C.  Hernandez,  Libert  ad  16, 
Madrid,  Spain.  Contains  a  great  deal  of  information  on  the  grow- 
ing of  olives  in  Spain,  pickling  of  olives,  and  the  manufacture  of 
oil.     In  Spanish. 

French  Process  and  Other  Processes — 

1.  J.  Bonnet.     L'Olivier,  1924.     Published  by  J.  B.  Bailliere  et  Fils,  19  Rue 

Hautfeuille,  Paris.  Price,  10  francs  plus  postage,  a  total  of  about 
15  frances,  about  95  cents,  American.  Written  by  the  foremost 
olive  expert  in  France. 

2.  A.  Rolet.     Les  Conserves  de  Fruits.      449  pages,  171  illustrations,  1913. 

Published  by  J.  B.  Bailliere  et  Fils,  19  Rue  Hautfeuille,  Paris. 
Original  price,  6  francs;  probably  not  less  than  15  francs  at  present. 

3.  Pour  1 'Olivier.     Comptes  rendu  des  Travaux  du  V°  Congres  International 

d'Oleiculture,  Marakech  et  Rabat,  1922.  Published  by  Libraire 
de  l'Institut  Agronomique,  58  Rue  Claude  Bernard,  Paris.  Price, 
501  francs.  This  is  the  proceedings  of  the  Fifth  International 
Congress  of  olive  culture.  The  proceedings  of  the  Sixth  Congress 
is  now  also  available  at  the  above  price.  Each  contains  numerous 
papers  by  experts  on  all  phases  of  the  olive  industry.     In  French. 


15m-9,'24 


STATION  PUBLICATIONS  AVAILABLE  FOR  FREE  DISTRIBUTION 


No. 

253.  Irrigation  and  Soil  Conditions  in  the 
Sierra  Nevada  Foothills,  California. 

261.  Melaxuma    of    the    Walnut,     "Juglans 

regia." 

262.  Citrus   Diseases   of   Florida    and   Cuba 

Compared  with  those  of  California. 

263.  Size  Grades  for  Ripe  Olives. 

268.  Growing  and  Grafting  Olive  Seedlings. 
273.   Preliminary  Report  on   Kearney  Vine- 
yard Experimental  Drain. 

275.  The  Cultivation  of  Belladonna  in  Cali- 

fornia. 

276.  The   Pomegranate. 

277.  Sudan  Grass. 

278.  Grain   Sorghums. 

279.  Irrigation  of  Rice  in  California. 

280.  Irrigation  of  Alfalfa  in  the  Sacramento 

Valley. 
283.  The  Olive  Insects  of  California. 

285.  The  Milk  Goat  in  California. 

286.  Commercial    Fertilizers. 

287.  Vinegar  from  Waste  Fruits. 
294.  Bean  Culture  in  California. 
298.   Seedless  Raisin  Grapes. 

804.  A  Study  of  the  Effects  of  Freezes  on 
Citrus   in   California. 

312.  Mariout  Barley. 

317.  Selections  of  Stocks  in  Citrus  Propa- 
gation. 

319.   Caprifigs  and  Caprification. 

321.   Commercial  Production  of  Grape  Syrup. 

324.  Storage  of  Perishable  Fruit  at  Freezing 

Temperatures. 

325.  Rice  Irrigation  Measurements  and  Ex- 

periments    in      Sacramento     Valley, 

1914-1919. 
328.   Prune  Growing  in  California. 
331.   Phylloxera-Resistant  Stocks. 

334.  Preliminary  Volume  Tables  for  Second- 

Growth  Redwood. 

335.  Cocoanut    Meal    as    a    Feed    for   Dairy 

Cows  and   Other  Livestock. 

336.  The   Preparation   of   Nicotine   Dust   as 

an  Insecticide. 
339.  The  Relative  Cost  of  Making  Logs  from 
Small    and    Large   Timber. 

343.  Cheese  Pests  and  Their  Control. 

344.  Cold  Storage  as  an  Aid  to  the  Market- 

ing of  Plums. 


BULLETINS 
No. 


347. 

348. 
349. 

350. 
351. 
352. 

353. 
354. 
355. 
357. 


358. 

359. 
860. 

361. 

362. 
363. 

364. 

366. 

367. 

368. 


370. 
371. 


372, 


373. 
374. 


375. 
376. 


for 
and 


and 


Cali- 


Almond  Pollination. 

The  Control  of  Red  Spiders  in  Decidu- 
ous Orchards. 

Pruning  Young  Olive  Trees. 

A  Study  of  Sidedraft  and  Tractor 
Hitches. 

Agriculture  in  Cut-over  Redwood  Lands. 

California  State  Dairy  Cow  Competition. 

Further  Experiments  in  Plum  Pollina- 
tion. 

Bovine  Infectious  Abortion. 

Results  of  Rice  Experiments  in   1922. 

The  Peach  Twig  Borer. 

A    Self-mixing    Dusting    Machine 
Applying       Dry       Insecticides 
Fungicides. 

Black     Measles,     Water    Berries, 
Related    Vine    Troubles. 

Fruit  Beverage  Investigations. 

Gum  Diseases  of  Citrus  Trees  in 
fornia. 

Preliminary  Yield  Tables  for  Second 
ftrowth  Redwood. 

Dust  and  the  Tractor  Engine. 

The  Pruning  of  Citrus  Trees  in  Cali- 
fornia. 

Fungicidal  Dusts  for  the  Control  of 
Bunt. 

Turkish  Tobacco  Culture,  Curing  and 
Marketing. 

Methods  of  Harvesting  and  Irrigation 
in  Relation  to  Mouldy  Walnut6. 

Bacterial  Decomposition  of  Olives  dur- 
ing Pickling. 

Comparison  of  Woods  for  Butter  Boxes. 

Browning  of  Yellow  Newtown  Apples. 

The  Relative  Cost  of  Yarding  Small 
and  Large  Timber. 

The  Cost  of  Producing  Market  Milk  and 
Butterfat  on  246  California  Dairies. 

Pear  Pollination. 

A  Survey  of  Orchard  Practices  in  the 
Citrus  Industry  of  Southern  Cali- 
fornia. 

Results  of  Rice  Experiments  at  Cor- 
tena,  1923. 

Sun-Drying  and  Dehydration  of  Wal 
nuts. 


CIRCULARS 

No.  No. 
70.  Observations    on    the    Status   of    Corn  161. 
Growing  in  California.  164. 
87.  Alfalfa.  165. 
111.  The  Use  of  Lime  and  Gypsum  on  Cali- 
fornia Soils.  166. 
113.  Correspondence  Courses  in  Agriculture.  167. 
117.  The    Selection    and    Cost    of    a    Small  170. 

Pumping  Plant. 

127.  House  Fumigation.  172. 

129.  The  Control  of  Citrus  Insects.  173. 
186.  Melilotus    indie  a    as    a    Green-Manure 

Crop  for  California.  174. 

144.  Oidium  or  Powdery  Mildew  of  the  Vine.  178. 

151.  Feeding  and  Management  of  Hogs.  179. 

152.  Some  Observations  on  the  Bulk  Hand- 

ling of  Grain  in   California.  184. 

158.  Announcement  of  the  California  State  190. 

Dairy  Cow  Competition,   1916-18.  193. 

154.  Irrigation  Practice  in  Growing  Small  198. 

Fruit  in  California.  199. 

155.  Bovine  Tuberculosis.  201. 

157.  Control  of  the  Pear  Scab.  202. 

158.  Home  and  Farm  Canning. 

160.  Lettuce  Growing  in  California.  203. 


Potatoes  in  California. 

Small  Fruit  Culture  in  California. 

Fundamentals   of    Sugar   Beet   Culture 

under  California  Conditions. 
The  County  Farm  Bureau. 
Feeding  Stuffs  of  Minor  Importance. 
Fertilizing  California  Soils  for  the  1918 

Crop. 
Wheat  Culture. 
The    Construction    of    the    Wood-Hoop 

Silo. 
Farm    Drainage  Methods. 
The  Packing  of  Apples  in  California. 
Factors    of    Importance    in    Producing 

Milk  of  Low  Bacterial  Count. 
A  Flock  of  Sheep  on  the  Farm. 
Agriculture  Clubs   in  California. 
A  Study  of  Farm  Labor  in  California. 
Syrup  from   Sweet  Sorghum. 
Onion  Growing  in  California. 
Helpful  Hints  to  Hog  Raisers. 
County   Organizations   for   Rural    Fire 

Control. 
Peat  as  a  Manure  Substitute. 


CIRCULARS — Continued 


No. 

205.  Blackleg. 

206.  Jack  Cheese. 

208.  Summary  of  the  Annual  Reports  of  the 

Farm  Advisors  of  California. 

209.  The  Function  of  the  Farm  Bureau. 

210.  Suggestions  to  the  Settler  in  California. 
212.   Salvaging  Rain-Damaged  Prunes. 

214.  Seed  Treatment  for  the  Prevention  of 

Cereal  Smuts. 

215.  Feeding  Dairy  Cows  in  California. 
217.  Methods   for   Marketing   Vegetables   in 

California. 

219.  The  Present  Status  of  Alkali. 

220.  Unfermented  Fruit  Juices. 

228.   Vineyard   Irrigation  in  Arid  Climates. 

230.  Testing  Milk,    Cream,    and    Skim   Milk 

for  Butterfat. 

231.  The  Home  Vineyard. 

232.  Harvesting    and    Handling    California 

Cherries  for  Eastern  Shipment. 

233.  Artificial  Incubation. 

234.  Winter  Injury  to  Young  Walnut  Trees 

during  1921-22. 

235.  Soil  Analysis  and  Soil  and  Plant  Inter- 

relations. 

236.  The  Common  Hawks  and  Owls  of  Cali- 

fornia  from    the    Standpoint  of  the 
Rancher. 

237.  Directions  for  the  Tanning  and  Dress- 

ing of  Furs. 

238.  The  Apricot  in  California. 

239.  Harvesting  and  Handling  Apricots  and 

Plums  for  Eastern  Shipment. 

240.  Harvesting    and    Handling    Pears    for 

Eastern   Shipment. 

241.  Harvesting  and  Handling  Peaches  for 

Eastern   Shipment. 

243.  Marmalade  Juice  and  Jelly  Juice  from 

Citrus  Fruits. 

244.  Central  Wire  Bracing  for  Fruit  Trees. 

245.  Vine  Pruning  Systems. 


No. 
247. 
248. 

249. 
250. 

251. 


252. 
253. 
254. 

255. 

256. 
257. 
258. 
259. 
260. 

261. 
262. 
263. 
264. 

265. 
266. 

267. 

268. 

269. 
270. 
271. 

272. 

273. 
275. 


Colonization  and  Rural  Development. 

Some  Common  Errors  in  Vine  Pruniag 
and  Their  Remedies. 

Replacing  Missing  Vines. 

Measurement  of  Irrigation  Water  on 
the   Farm. 

Recommendations  Concerning  the  Com- 
mon Diseases  and  Parasites  of 
Poultry    in    California. 

Supports  for  Vines. 

Vineyard   Plans. 

The  Use  of  Artificial  Light  to  Increase 
Winter  Egg  Production. 

Leguminous  Plants  as  Organic  Fertil- 
izer in  California  Agriculture. 

The  Control  of  Wild  Morning  Glory. 

The  Small-Seeded  Horse  Bean. 

Thinning  Deciduous  Fruits. 

Pear  By-products. 

A  Selected  List  of  References  Relating 
to  Irrigation  in  California. 

Sewing  Grain  Sacks. 

Cabbage  Growing  in  California. 

Tomato  Production  in  California. 

Preliminary  Essentials  to  Bovine  Tuber- 
culosis Control. 

Plant  Disease  and  Pest  Control. 

Analyzing  the  Citrus  Orchard  by  Means 
of  Simple  Tree  Records. 

The  Tendency  of  Tractors  to  Rise  in 
Front;  Causes  and  Remedies. 

Inexpensive  Labor-saving  Poultry  Ap- 
pliances. 

An  Orchard  Brush  Burner. 

A  Farm  Septic  Tank. 

Brooding  Chicks  Artificially. 

California  Farm  Tenancy  and  Methods 
of  Leasing. 

Saving  the  Gophered  Citrus  Tree. 

Marketable  California  Decorative 
Greens. 


